R'EPORT ;Cr-H OF THE CANADIAN ARCTIC EXPEDITION 1913-18 VOLUME IX: ANNELIDS, PARASITIC WORMS, PROTOZOANS, ETC. PART G-H: TREMATODA AND CESTODA By A. R. COOPER SOUTHERN PARTY, 1913-16 fiOTTAWA THOMAS MULVEY PRINTER TO THE KING'S MOST EXCELLENT MAJESTY 1921 Issued February -1th 1921 Report of the Canadian Arctic Expedition, 1913-18. VOLUME I: GENERAL INTRODUCTION, NARRATIVE, ETC. Part A: NORTHERN TARTY, 1913-18. Part B: SOUTHERN PARTY, J«.M:M6. By Rudolph Martin Anderson (In -preparation}. VOLUME II: MAMMALS AND BIRDS Part A: MAMMALS OF WESTERN ARCTIC AMERICA. By Rudolph Martin Anderson. (In preparation). P. A. Part B BIRDS OF WESTERN ARCTIC AMERICA. By R. M. Anderson and P. A. Taverner. (In preparation). VOLUME III: INSECTS INTRODUCTION. By C. Gor.lon Hewitt (Issued December 10, 1920 Part A: COLLEMBOLA. By Justus W. Folsom (Issued July 10, 1919). Part B: NEUROPTEROID ^INSECTS. By Nathan Banks (Issued July 11, 1919). Part C: DIPTERA. Crane-flies. By Charles P. Alexander. Mosquitoes. By Harrison G. Dyar. Diptera (excluding Tipulidai and Culicidee). By J. R. Malloch (Issued July 14, 1919). Part D: MALLOPHAGA AND ANOPLURA. Mallophaga. By A. W. Baker. Anoplura. By G. F. Ferris and G. H. F. Nuttall (Issued September 12, 1919) . Part E: COLEOPTERA. Forest Insects, including Ipidce, Cerambycidse, and Buprestidse. By J. M. Swaine. CarabidiB and Silphid®. By H. C. Fall. Coccinellidse, Elateridse, Chrysomelidje and Rhynchophora. (excluding Ipidce). By C. W. Leng. Dytiscidse. By J. D. Sherman, Jr (Issued December 12, 1919) . Part F: HEMIPTERA. By Edward P. VanDuzee (Issued July 11, 1919). Part G: HYMENOPTERA AND PLANT GALLS. Sawflies. (Tenthredinoidea). By Alex. D. MacGillivray. Parasitic Hymenoptera. By Charles T. Brues. Wasps and Bees. By F. W. L. Sladen. Plant Galls. By E. Porter Felt (Issued November S, 1919). Part H: SPIDERS, MITES AND MYRIAPODS. Spiders. By J. H. Emerton. Mites. By Nathan Banks. Myriapods. By Ralph V. Chamberlin (Issued July 14, 1919). Part I: LEPIDOPTERA. By Arthur Gibson (Issued, January 10, WW). Part J: ORTHOPTERA. By E. M. Walker (Issued September 4, 1920). Part K: INSECT LIFE ON THE WESTERN ARCTIC COAST OF AMERICA. By Frits Johansen (In press). VOLUME IV: BOTANY Part A: FRESHWATER ALGAE AND FRESHWATER DIATOMS. By Charles W. Lowe. (In 'preparation). Part B: MARINE ALGAE. By F. S. Collins (In preparation). Part C: FUNGI. By John Dearness " (In preparation). Part D: LICHENS. By G. K. Merrill (In preparation). Part E: MOSSES. By R. S. Williams (In press). VOLUME V: BOTANY Part A: VASCULAR PLANTS. By James M. Macoun and Theo. Holm. . . . . (In press). Part B: CONTRIBUTIONS TO THE MORPHOLOGY, SYNONYM Y.AND GENERAL DISTRI- BUTION OF ARCTIC PLANTS. By Theo. Holm (In press) Part C: GENERAL NOTES ON ARCTIC VEGETATION. By Frits Johansen. (In preparation). VOLUME VI: FISHES, TUNICATES, ETC. Part A: FISHES. By F. Johansen (In preparation). Part B: ASCIDIANS, ETC. By A. G. Huntsman (In preparation). VOLUME VH: CRUSTACEA Part A: DECAPOD CRUSTACEANS. By Mary J. Rathbun (Issued August 18, 1919). Part B: SCHIZOPOD CRUSTACEANS. By Waldo L. Schmitt (Issued September 22, 1919). Part C: CUMACEA. By W. T. Caiman (Issued October 15, 1920). Part D: ISOPODA. By P. L. Boone (Issued November 10, 1P?0) Part E: AMPHIPODA. By Clarence R. Shoemaker (Issued September 7, 1920). Part F: PYCNOGONIDA. Leon J. Cole (Issued January 8, 19*1). Part G: EUPHYLLOPODA. By F. Johansen (In preparation). Part H: CLADOCERA. By Chancey Juday (Issued June 2S, 1920). Part I: OSTRACODA. By R. W. Sharpe (In preparation). Part J: FRESHWATER COPEPODA. By C. Dwight Marsh (Issued April 21, 1920 Part K: MARINE COPEPODA. By A. Willey (Issued June 25, 1920). Part L: PARASITIC COPEPODA. By Charles B. Wilson (Issued August 6, 1920). Part M: CIRRIPEDIA. By H. A. Pilsbry (In preparation). REPORT OF THE CANADIAN ARCTIC EXPEDITION 1913-18 VOLUME IX: ANNELIDS, PARASITIC WORMS, PROTOZOANS, ETC. PART G-H: TREMATODA AND CESTODA By A. R. COOPER SOUTHERN PARTY, 1913-16 OTTAWA THOMAS MULVEY PRINTER TO THE KING'S MOST EXCELLENT MAJESTY 1921 Issued February 4th 1921 Trematodes and Cestodes of the Canadian Arctic Expedition, 1913-18. A. R. COOPER. (With two plates.) INTRODUCTION. The trematodan and cestodan fauna of the Arctic regions has received not a little attention from investigators up to date, but only a comparatively small amount of material has been collected from that part of the area bordering on the North American continent. It is to Fabricius (1780), who investigated the first of this material which was obtained in Greenland, that we must go for the earliest descriptions of many of our species. Krabbe (1865) studied the avian cestodes in particular and described many species also from Greenland. Zurn (1874) and Comini (1887) dealt with material collected by two polar expeditions and Bergendal (1892) investigated to a certain extent the parasitic fauna of Northern Greenland. , But the latest and most important papers are those by Zschokke (1903), Linstow (1905) and Odhner (1905). Zschokke and Odhner studied the cestodes and trematodes, respectively, obtained by the German Expedition of 1898 to Spitzbergen and the neighbouring islands of the Arctic ocean, and Linstow, the nematodes, acanthocephala and cestodes collected by the Russian Polar Expedition of 1900 to 1903. So far as I am aware the parasitic fauna of the Arctic coasts of Eastern Siberia, Alaska and Canada has not up to the present been investigated, but the collections made by the Canadian Arctic Expedition, in so far as they have already been reported upon, show that the region is rich in new forms and worthy of further extensive study. MATERIAL. The material, which was all obtained by Mr. Frits Johansen, consists of one species of trematode only and sixteen species of cestodes. The latter include four considered to be new, one belonging to the genus Aploparaksis which was not determined with certainty specifically, and two larval members of the genus Diphyllobothrium. To this there are addied one species of ectoparasitic trema- tode, namely, Epibdella hippoglossi, which were collected by Mr. C. H. Young, and one of cestode, Abothrium rugosum, collected by Mr. Johansen in Nova Scotia. It is thought that since they were also found by Fabricius in Greenland and by Linstow in the European portion of the Arctic Ocean, respectively, and consequently belong to the Arctic fauna, they might well be included here. The writer has some new data on one of them in particular to submit. The trema- todes and cestodes are dealt with together in this paper on account of the small number of the former. The following table shows their distribution as regards hosts, localities and dates: — 9133-1* 1 (,-H Canadian Arctic Expedition, 1913-18 ORDS <»i i HI . . .. i i RRENCE <>!' TREMATODE8 AND CESTODES IX UnsT.- <»r ARCTIC AMERICA. Para Hosts. Local iti,-. Dates. Trematodea: '•(/»•//« A/y»y»cf//i».v.sj (h tints itltnu'hnii^ arc tic us.. tea: .^chixtuct idiulu* 9Qtidvt J)il>hi/llt>hothiiuni .-p. l:ii\ < 'yathocephalus americanitf... AofArtfflOJItM intrrtmdius. . . . .. Bothrioccphalus scorpii Abothrium rugosum •> .. u Abothrium cruxtmm i iah: ////-/•.'(//".V.-//.S IktppoflrloMiw. . N!:iiiini:il: Lc Have Island, Nova Scotia Bernard harbour, Dolphin and Union strait, Northwest Territories ( '.-m. Bernard harbour, Lake at lirnianl harbour, Lake at liernard harbour, Lake at Collinson point, Alaskan Arc- tic coast. Cockbuni point, Bernard har- bour. Marsh River, Collinson point.. St. Andrews, New Brunswick. Cockburn* point . . . AUK. 9, 1910. Oct. 18, I'.M.-J. .lulv l~>. 1915.. Oct. 1, 1915. April, lOKi. JulyS, I'M 4. Aug. 30, 1914, Sept. i;, 1914, End oi 1915. July I'.', l'.M4. Julv, Aug., 1919. Aug. 30, 1914, I'l/'jnxtfii* puniiitiux % Snnv namaycush Sinaksis sp Soniatiria v-nigra Pi win i«/v<; intermedia Diphyllobothrium cordatuni. Diphyllobothrium lanceola- fUlti. Diphyllobothrium sp. larv. . . Pyramicoccphalus phocarum. « « (larval), ratwifl cocnurus Somateria v-nigra Mammals: Erignathus barbatus « «< « « Dolphin and Union strait Bernard harbour « «< U «( P/wca hispida Canw familiaris Collinson point « a Trematodes and Cestodes 5 G-H Class I TREMATODA Order I HETEROCOTYLEA Monticelli 1892 Family TRISTOMIDAE Cobbold 1877 Subfamily TRISTOMINAE Monticelli 1892 Genus Epibdella Blainville 1828 Epibdella hippoglossi (O. F. Muller 1776) (Figs. 1 and 2.) 1776: Hirudo hippoglossi O. F. MULLER 1776: 220 (Type host, Hippoglossus; Denmark) 1780: Hirudo hippoglossi FABRICIUS 1780: 320 1788: Hirudo hippoglossi O. F. MULLER 1788: 18 1790: Hirudv hippoglossi GMELIN 1790: 3098 1815: Phylline hippoglossi OKEN 1815 1828: Epibdella hippoglossi BLAINVILLE 1828: 567 1843: Tristoma hamatum RATHKE 1843: 238 ?1850: Phylline hippoglossi DIESING 1850: 426 1858: Epibdella hippoglossii BENEDEN 1858: 21 1864: Epibdella hippoglossi BENEDEN and HESSE. 1864: 69 1878: Nitzschia hippoglossi TASCHENBERG 1878: 568 1890: Epibdella hippoglossi BRAUN 1890: 411, 527, etc. 1891: Epibdella hippoglossi MONTICELLI 1891: 105, 125, etc. 1896: Epibdella hippoglossi SCHOTT 1896: 253 1899: Phyllonella hippoglossi GOTO 1899: 264 1902: Epibdella hippoglossi MONTICELLI 1902: 137, etc. 1904 : Epibdella hippoglossi STAFFORD 1904 : 482 1905: Epibdella hippoglossi ODHNER 1905: 370 Specific diagnosis. — With the characters of the genus. Medium large trematodes with elongated, ovoid body having a length and a breadth (exclusive of the posterior organ of adhesion) of 12 to 24 and 8 to 11 mm., respectively. Slightly constricted behind the anterior organs of adhesion. Latter elongated, not excavated and only slightly separated from the body, 1 • 85 mm. in length by 1-0 in width. Posterior sucker orbicular, 4 to 5-5 mm. in diameter; somewhat thickened anteriorly; inner (ventral) surface provided with small tubercles, radiating posteriorly; anterior hooks almost straight, considerably protruding, 0-56 to 0-77 mm. in length, middle, much curved, 0-86 to 1-40, posterior, with minute hook at tip, 0 • 99 mm. Mouth median, ventral and opposite the constriction ("neck"), provided with indistinct lips. Ptiarynem>ir: th«- Lanital >iims was a little shallower; the posterior end ui tin- cimi.-- level behind the acetabulum about two-fifths of the distance i'mm it TO the anterior testis; the ovary was almost exactly spherical rather than "trans- versely oval"; but all of these differences are considered to he minor variations and not of sufficient importance to affect the diagnosis of the species. Class II CESTODA Subclass CESTODA s. str. Order 1 PSEUDOPHYLLIDEA Carus 1863, nee Luhe 1910, nee Cooper 191 U, e.p. 1'olyzootic, seldom monozootic, cestodes with mostly unarmed scolex with- out rostellum or proboscis formation, excepting in the Haplobothriinae where t he prima ry scolex is provided with four protrusible proboscides resembling those of the Trypanorhyneha. Usually with two weakly developed sucking grooves, which in individual cases are modified by the strong development of their walls or by more or less extensive fusion of their edges, so that they may appear funnel- shaped or tubular, which may also unite with each other more or less completely to form an unpaired terminal adhesive organ, or become rudimentary or entirely absent, in which latter case they are replaced by a terminal functional organ of attachment. The development of a pseudoscolex takes place occasionally. Xo headstalk (as in the Trypanorhyneha) . External segmentation more or less pro- nounced in the cases of multiplicity of the genital organs, only seldom completely absent. Genitalia in each segment usually single, seldom double. Their devel- opment proceeds from ahead backwards only in their beginning and does not continue to a degeneration of the reproductive glands; but the majority of the proglottides, being at the same stage of development, bring their sexual product < to maturity at the same time, so that in all of them new eggs are formed continu- ously and all the eggs of the whole animal are at the same stage of development. A surficial opening of the uterus is always present. Testes numerous; vas deferens strongly coiled, without a true seminal vesicle. Ovary near the posterior end of the proglottis, mostly median in the case of single genitalia, seldom approaching the margin of the strobila bearing the genital opening (that of the cirrus and vagina). Vitelline follicles very numerous, mostly in the cortical, seldom in the medullary parenchyma. Uterus a more or less winding canal, the individual coils of which converge somewhat towards the centre of the proglottis to form the so-called rosette; but in other forms it enlarges to form a capacious cavity, the uterus-sac, from which the duct-like beginning of the uterus is sharply separated. Eggs operculate or non- operculate, developing mostly only after being laid, but in other cases within the uterus. This diagnosis of the order is that which I recently (1919:301) published, revised to include the family Caryophyllaeidae Liihe 1910, e.p. Cooper 1920, which, after my study of Glaridacris catostomi, I agree with Liihe rightly belongs to the Pseudophyllidea. Family I DIPHYLLOBOTHRIIDAE Liihe 1910, e.p. Cooper 1919 Subfamily I LIGULINAE Liihe 1899 Genus Schistocephalus Creplin 1829 Schistocephalus solidus (0. F. Muller 1776) For a synonymy and a diagnosis of this species see Cooper, 1919: 318-29. Habitat. — The abdominal cavity of Pygosteus pungitius L., a stickleback; lake at Bernard harbour, July 15, 1915; C.A.E. Station 40j. Only one worm from each of two specimens of the host was taken. Trematodes and Cestodes 9 G-H Subfamily II DIPHYLLOBOTHRIINAE Ltihe 1910 Genus I Diphyllobothrium Cobbold 1858, e.p. Liihe 1910 Diphyllobothrium canadense, sp. nov. (Figs. 4, 5, 11.) Specific diagnosis.— With the characters of the genus. Large cestodes at least 235 mm. in length and 6-5 in maximum width. Scolex small, elongated, rectangular in outline surficially and laterally, excepting for rounded summit, 0-84 mm. in length, 0-37 in width at base and 0-46 in thickness at middle. Bothria long and narrow, not sharply separated posteriorly from surfaces of strobila. Neck, 0-7 mm. in length. First segments, 0-045 mm. in length by 0-50 in width; width of segments 30 mm. from scolex, 3-0 mm., 37-5 from scolex, 3-5 by 0-65 in length. At about its middle, where the segments are 6-5 mm. in width by 0-60 in length, the strobila is ruffled or frilled laterally. Hindermost gravid segments from two or more to one and a half times as broad as long anteroposteriorly. Posterior borders moderately prominent throughout. Cuticula 4 • 5/j, in thickness, outer half cirrous. Main longitudinal parenchy- matous muscles scarcely arranged in fascicles, whole layer 35ju in thickness. Calcareous bodies ellipsoidal in shape, at least 10 p in length. Nerve strands 0 • 22 to 0-23 of width of proglottis from margins. Rudiments of the genitalia appear 6 mm. behind the scolex, the first eggs about 20 mm. Genital cloaca median, one third of the length of the segment from its anterior border, 160^ in diamter by 80 in depth. Vaginal opening immediately behind that of cirrus and very slightly to one side; beginning of vagina alternates irregularly from right to left opposing the lower portion of the cirrus-sac. Testes continuous from proglottis to proglottis and from side to side between the consecutive, centrally located sets of female genitalia; at least 150 in number; ellipsoidal in shape, the greatest diameter being transverse, 55 to 90ju in length, 110 to 145 in width and 60 to 90 in depth. Vas deferens 25/* in diameter; only slightly coiled dorsal and somewhat posterior to the cirrus-sac, coils 0- 14 mm. in length, 0-40 in width and 0-20 in depth. Seminal vesicle spheroidal, thick- walled, muscular, posterodorsal to cirrus-sac and a little to one side of the med- ian line directly above the beginning of the vagina, 90 to 145ju in diameter. Vas deferens 18/z in diameter as it pierces the wall of the cirrus-sac in the median line, only slightly enlarged and coiled in the dorsal half of the cirrus-sac. Cirrus, 40 to 55^ in diameter, occupies the ventral half of the pouch. Cirrus-sac ovoid in shape with the narrower end ventral; dorsal end deflected slightly from the median line to the side opposite that occupied by the seminal vesicle and the beginning of the vagina; 0-30 to 0-32 mm. in length (depth) by 0-15 to 0-20 in diameter; connected to the dorsal body-wall by numerous stout retractor muscle-fibres, many of which pierce its wall and are attached to the proximal end of the cirrus proper at the middle of the sack. Just within its opening the vagina, slightly enlarged to a diameter of 40/x, curves dorsally and somewhat aside to reach the median line and take a straight course posteriorly close against the ventral wall of the medulla. Half way along its course it is reduced to 22/* in diameter. Above the ovarian isthmus it gradu- ally becomes enlarged to as much as 100/z in diameter to form an elongated seminal receptacle, having comparatively thick walls. Spermiduct 30ju in length by SM in diameter. Ovary near the posterior border and ventral musculature of the proglottis, 0-50 to 1-30 mm. in width by 0-18 to 0-28 in length by 0-20 in thickness, irregularly lobulated laterally, the lobules intermingling somewhat with the coils of the uterus; isthmus 60/z in diameter. Oooapt 28 to 30// in diameter. Vitelline follicles closely crowded together, continuous from segment to segment and at the margins and anterior and posterior borders of the proglot- 10 G-H Canadian Arctic Expedition, 1913-18 tides, leaving free more or less circular areas above and below the uterus and somewhat smaller than the uterus; 1,500 to 2,000 per segment; ellipsoidal in shape with the longitudinal axes dorsoventral, slightly compressed anteroposter- iorly; average length, width and depth, 40, 75 and 85ji, respectively. Common vitelline duct short, expands to form a reservoir 35 to 40/z in diameter just before joining the oviduct. Shell-gland diffuse, some of its cells extending to the ventral musculature. Uterine rosette circular or elliptical in surficial view, 0-85 to 1-20 mm. in length, 1-20 to 1-70 in width and 0-50 to 0-60 in depth, composed of 8 to 10 coils on each side of the median line, the most anterior pair of which pass forward on each side of the cirrus-sac. In the oldest segments the walls of the uterus break down, thus converting the rosette into a more or less undivided sac. Opening of uterus at the centre of the proglottis, 70 to 75/z in diameter. Eggs, brownish yellow in colour, ellipsoidal in shape, 56 to 59ju in length by 37 to 39/u in diameter; operculum 15 to 20ju in diameter, shell 2-5 to 2 -8/4 in thickness; boss at the end opposite that bearing the operculum, 4ji in diameter. Type host. — Corvus corax principalis Ridg., the northern raven, in the intestine. Type locality. — Bernard harbour, Northwest Territories, Canada. Collected by Mr. Frits Johansen, August 29, 1915. Cotypes are deposited in the Victoria Memorial Museum, Ottawa, Canada, (Annelids, etc., catalogue No. 76), and in the collection of the writer at Chicago, U.S.A. This form obviously does not belong to any of the three species of Diphyllo- bothrium which have been described from birds in Europe, namely, D. ditremum (Creplin), D. dendriticum (Nitzsch) and D. fissiceps (Creplin), the first of which was reported by Linstow (1905: 16) from a young male Larus glaucus F. from West-Taj myr, Middendorffsbay. However, it resembles in many respects Dibothrium cordiceps Weinland as described by Linton (1891) from Pelecanus < rythrorhynchus at Yellowstone Lake. The superficial characters and measure- ments of the two forms agree fairly well, while the anatomy of D. cordiceps is undoubtedly that of a species of Diphyllobothrium — as suggested by Ward (1918:432) — very close to if not indentical with this cestode. In D. canadense, however, I saw no distinct expansion of the vagina at its beginning to form an outer seminal receptacle, as described by Linton, nor eggs with measurements as large as those he gave, namely 70 by 35/x. Consequently until D. cordiceps is removed from the species inquirendae, it seems advisable to record this form under a new name. Diphyllobothrium cordatum (Leuckart 1863) This species has been sufficiently described for diagnostic purposes by Zschokke (1903:4-6). Seven specimens were found in company with D. lanceolatum and Pyramico- cephalus phocarum, the next two species, in the lot of material labelled, "From the intestinal channel of Phoca [Erignathus] barbata, Bernard harbour, North- Jl west Territories, July 4, 1915, C.A.E. Station 4Qt,u." The three largest specimens, somewhat larger than those described by Zschokke, had the following dimensions: 136 mm. in length by 4 in width, 140 by 6 and 154 by 6-5. The scolices were somewhat smaller, being only 1-3 mm. in length and depth as compared with 1 • 8 and 1 • 8 given by Zschokke and 2 and 2 by other writers. Including the two or three smallest and most posterior loops of the uterus there were 8 to 10 loops on each side of the median line rather than 6 to 8; and the eggs measured 70 to 72/z by 50)U in alcohol and 62 to 68 by 41 to 45ju in synthetic oil of wintergreen in which the specimens studied were cleared. These data indicate, incidentally, the marked variability in the shape and dimensions of the eggs after complete dehydration and the consequent Trematodes and Cestodes HG-H necessity of measuring them in the original preserving fluid if not in the fresh condition, especially in view of the fact that in this regard the species of Diphyllo- bothrium which have been reported from seals approach each other so closely as to overlap in many cases. Diphyllobothrium lanceolatum (Krabbe 1865) This species has also been well described by Zschokke (1903:6-9). Habitat. — Intestine of Erignathus barbatus (Erxleben), as follows: T^A. THE OCCURRENCE OF DIPHYLLOBOTHRIUM LANCEOLATUM IN ERIGNATHUS BARBATUS IN ARCTIC AMERICA. Locality. Date. C.A.E. Station. Accompanied by Bernard harbour Northwest Territories Aug. 24, 1914 Oct 3 1914 37a 37o m,u Wt,u 42e P. phocarum. D. cordatum. P. phocarum. D. sp. larv. P. phocarum. Dolphin and Union strait, Northwest Territories Bernard harbour July 4, 1915 « « July 4^8, 1915 Sept. 3, 1915 " " The material studied differed from that studied by Zschokke in the following points: The specimens were larger, the dimensions of three of the largest being, 50 by 2-9 mm., 59 by 4 and 68 by 3; the most anterior coils of the uterus were not strictly to the right and left of the cirrus-sac but rather behind the middle of it; eggs appeared first in the 45th to 60th segment, instead of the 30th, and they were longer — 64 to 68ju by 40ju (cf. Zschokke's 62 by 40/z). Diphyllobothrium sp. larv. A large number of larval diphyllobothria varying in length from 6 to 25 mm. and in width from 0- 6 to 2- 5 mm. were found in company with D. lanceolatum in the lot of material collected on July 4, 1915 at C.A.E. Stations 40£ and u. They are considerably depressed, lanceolate in shape, and correspond with those described by Zschokke (1903:12-13, Fig. 17, Taf. II) as accompanying larvae of D. schistochilos (Germanos) in the intestine of P. barbata and doubtfully con- sidered by him as being larvae of D. schistochilos. The material in question resembles D. lanceolatum rather than the latter species as described by Germanos (1895), but on account of the fact that there were present in the lot of material no specimens intermediate in size between the largest of the larvae and the smallest of those diagnosed as D. lanceolatum I cannot say positively that they are larvae of the latter species. Diphyllobothrium sp. larv. (Figs. 6, 7.) To this genus there is also referred a lot of four poorly preserved bothrio- cephalid larvae which were found in the intestine of a red Canadian trout, Salvelinus marstoni Garman, from a lake at Bernard harbour, on October 1, 1915, C.A.E. Station 42o,r, in company with Abothrium crassum and Proteoce- phalus arcticus (vide infra). The specimens are all about 9 mm. in length and from 0-6 to 0-9 mm. in width. The scolex (Figs. 6, 7) bears two elongated, dorsoventrally situated bothria with comparatively thin walls, and on the whole resembles that of species of Diphyllobothrium rather that that of species of Both- 12(1-11 Canadian A relic /<:.*•/>/•, •/////>//. 1913-18 riocephalus. The body is depressed and ligulate, the margins being parallel for almost the whole Irngth :md the posterior end gradually tapered to a diameter .-lightly smaller than the tip of the scolcx. On the whole these larvie resemble others that I have taken from cyst- in the wall of the stomach <»f Lota maculosa (LeSueur), the burbot, at Port Credit, < >n tin-in, near Toronto, and at Charlevoix, Michigan, and which may be similar to those NicUerson i 1906) found in fishes from the Great Lakes but suspected might. belong to Bpeoiefi other than Diphyllobothrium latum, the broad human Ui4Klworiii^, Incidentally the writer is conducting feeding experiments with fn"e Tarvsefrom the burl)ot in an endeavour to ascertain whether they are young of I), latum and whether the cases of infection with this cestode in America can lie accounted for in this direction. Genus II Pyramicocephalus Monticelli 1890 Pyramicocephalus phocarum (Fabricius 1780) This species, described by Linstow (1905:14-15) under the name of P. aniho- cephalus (Rud.), was collected from Erignathus barbatus (Erxleben), bearded seal, as follows: THE OCCURRENCE OF PYRAMICOCEPHALUS PHOCARUM IN ERIGNATHUS BARBATUS IN ARCTIC AMERICA. Locality. Date. C.A.E. Station. Accompanied by. Bernard harbour, Northwest Territories « «< « « « Aug. 24, 1914... July 4, 1915 Sept. 3, 1915 37a 40/,w \2c D. lanceolatuni. I), (ordntntn. D. lanceolatuni. The largest specimen, one from Station 40£,w, measured 900 nun. in length by 6 mm. in maximum width and its scolex, 4 mm. in length, 2 in width and 3 in depth. Another from the same lot was 320 mm. by 5 in dimensions. The eggs, when measured in the sections, were found to vary from 58 to 65^t in length by 34 to 39 in width. Linstow gave their measurements as 65 by 39ju. Two larvae, as well as adults, were found in the material from Station 4Qt,u, while another larva was all that was taken from a specimen of common rough seal, Phoco hispida Schreber, at Collinson point, Alaska, on September 7, 1913, at Station 27 j. Subfamily III Gyathocephalinae Liihe 1899, e.p. Cooper 1919 Genus I Cyathocephalus Kessler 1868 Cyathocephalus americanus Cooper 1917, e.p 1917: Cyathocephalus americanus.. . .COOPER 1917: 35 (Type host, Coregonus clupeiformis, whitefish, Georgian Bay, L:;kc Huron) 1919: Cyathocephalus americanus.. . . COOPER 1919: 341 Specific diagnosis. — With the characters of the genus. Small cestodes, attaining a length of at least 16 mm. with a maximum breadth of 1-7 mm. Scolex funnel-shaped, 0 • 3 to 0 • 9 mm. long and 0 • 5 to 1-50 broad, with a revolute margin. Neck 1-0 to 3-0 mm. in length. Segments twice as broad as long, terminal one rounded. Trematodes and Cestodes 13 G-H Cuticula 5 to 6/* in thickness, with neither hooks nor spines; sub-cuticula 25 to 4%. Ten to twenty sets of genitalia, beginning 1 -5 to 5-0 mm. from the anterior end. Strong tendency for the reproductive apertures to lie all on one surface of the strobila. Vagina opens behind the uterus. No papillae around the female opening but the atrium is surrounded by a sphincter from 15 to 30^ in thickness. Testes in two lateral fields in the medulla of the anterior portion of the proglottis, 60 to 115)U in diameter. Coiled vas deferens antero-dorsal to the cirrus-sac ; no seminal vesicle before entering the cirrus-sac nor connective tissue sack surrounding the whole duct. Protruded cirrus 0-2 mm. in length. by 0- 12 in diameter at base, Cirrus-sac ovoid in shape, 0-20 to 0-26 mm. in length by 0-18 in diameter; no retractors connecting it with the dorsal body-wall; large mass of glandular pigmented cells surrounding it dorsally and laterally. Vagina 12 to 18^ in diameter; no sheath near its opening; receptaculum seminis 35 to 75ju in diameter. Spermiduct very short and narrow, 20 to 25 by 8 to 9/*, respectively. Ovary tubulolobular, fan-shaped; wings extend laterally and dorsally around the central connections of the female ducts; isthmus prominent, 0-18 by 0-12 mm., ova in same, 12 to 15/i in diameter. Oocapt 25 to 28/x in diameter. Vitelline follicles continuous from proglottis to proglottis, forming a layer 75 to 90/z thick in the cortical parenchyma, 20 to 35 in transec- tions. Shell-gland dorsal. Uterine rosette not surrounded by a muscular sac, but the organ is enveloped proximally by numerous shell-glands. Eggs, 40 by 30M. Habitat. — The intestine of Cristivomer namaycush (Walbaum), the lake trout; lake at Bernard harbour, C.A.E. Station 500, April, 1916. Only one specimen was found in the material from Station 50#, which other- wise belonged to Abothrium crassum, Echinorhynchus salvelini and E. coregoni, and, while undoubtedly belonging to C. americanus, was in many respects much larger than any of those formerly studied. Consequently I submit the above partly emended specific diagnosis to cover this case. The most striking anatom- ical feature presented by this specimen is the comparatively large sphincter muscle surrounding the aperture of the female genital atrium, a structure which I have also been able to find on re-examination of the material upon which the original description of the species was based. Genus II Bothrimonus Duvernoy 1842, e.p. Cooper 1919 Bothrimonus intermedius Cooper 1917, e.p. 1917: Bothrimonus intermedius COOPER 1917: 35 (Type host, Pseudopleuronectes americanus; St. Andrews, New Bruns- wick) 1919: Bothrimonus intermedius COOPER 1919: 351 Specific diagnosis. — With the characters of the genus. Small cestodes up to 50 mm. in length and 2-8 in width. Scolex almost spherical, 0-48 to 0-72 mm. long, 0-50 to 0-84 wide and 0-60 to 1-0 thick. Bothria hemispherical, their apertures ordinarily not fused to form a single terminal opening. Strobila uniform in width from a short distance behind the scolex to the posterior end; 0-4 to 0-6 mm. in thickness; slightly more convex ventrally than dorsally. Cuticula, 5 to 10/j, in thickness. Nerve strands 12 to 20ju in diameter; each divides into two branches sagitally before entering the scolex; transverse commissure diffuse. Four main excretory trunks in ripe proglottides, six farther forward passing into the scolex; all in the medullary parenchyma. Reproductive organs begin 0-3 to 1-5 mm. from the scolex; up to 160 in number. Weak sphincter around the common female cloaca. Vagina opens close behind the uterine pore which is not quite in the median line. 14G-H Canadian Arctic Expedition, 1913-18 Testes in two lateral fields and two layers between the excretory trunks, continuous from proglottis to proglottis; spherical in shape, 75 to 10(V in din meter. Coils of vas deferens anterodorsal to cirrus-sac, the duct 15 to 30/x in diameter, depending on the amount of spermatozoa it contains. Cirrus-sac oval, 0-23 to 0-29 by 0-15 to 0-17 mm.; everted cirrus, 60 by 85/z. Vagina, 10 to 25/i in diameter; receptaculum seminis, 40 to 60^; spermiduct 10/z. Ovary crescentic in shape, wings tubulolobular; isthmus almost spherical, 0-1 mm. in diameter. Oocapt, 25 to 30/i in diameter, oviduct 15 to 20/z. Com- mon vitelline duct 120 by 30/x. Vitelline follicles spherical, 60 to 90/i in diameter; in the lateral thirds of the strobila, continuous at the margins of the same and from proglottis to proglottis. Shell-gland obscure. Uterus surrounded by glandular cells proximally; 0-25 mm. in maximum diameter. Eggs, 36 to 40 by 24 to 25ju in dimensions. Habitat. — The intestines of Salvelinus malma (Walbaum) and a whitefish, Coregonus sp. as follows:— THE OCCURRENCE OF BOTHRIMONUS INTERMEDIUS IN HOSTS OF ARCTIC AMERICA. Host. Locality. Date. C.A.E. Station. Salvelinus malma Collinson point, Alaskan Arctic Coast. Cockburn point, Bernard harbour, Northwest Territories. Marsh river, Collinson point, Alaska. July 8, 1914 28o 37d 37fc 41« 28p Aug. 30, 1914 « « « « Coregonus sp Sept. 6, 1914 End of August, 1915. July 12 1914 As in the case of Cyathocephalus americanus the original diagnosis of this species is here amended in part owing to the fact that the material listed above gave measurements which are considerably larger than those set forth previously by the writer. Other characters of a qualitative nature, however, clearly indicate that the form belongs to B. intermedius and is quite different from the European and other species, of which B. olrikii (Krabbe 1874) ( = Dipllocotyle olrikii) was found in Samo carpio in Greenland, and B. cohaerens (Linstow 1903.) ( = D. cohaerens) in Pleuronectes flesus on the Murman coast. I should like, furthermore, to take this opportunity of adding a fourth host for this species of cestode, namely Zoarces anguillaris (Peck), the eelpout, from which Dr. W. A. Clemens of the University of Toronto obtained several lots of material at St. Andrews, New Brunswick, in the summer of 1919, and sent them to me recently for determination. Family II PTYCHOBOTHRIIDAE Liihe 1902 Sub-family I Ptychobothriinae Liine 1899 Genus Bothriocephalus Hud. 1808, e.p. Luhe 1899, e.p. Cooper 1919 Bothriocephalus scorpii (Muller 1776) For a comprehensive synonymy and a diagnosis of this species see Cooper, 1919: 384-402. Habitat. — Intestine of Oncocottus quadricornis L., four-horned sculpin, Bernard harbour and Cockburn point, August 30, 1914, C.A.E. Station 37d, and August, 1915, Station Trematodes and Cestodes 15 G-H Subfamily II AMPHIGOTYLINAE Luhe 1902 Genus Abothrium Beneden 1871, char, emend. Luhe 1899 Abothrium rugosum (Batsch 1786) For a description and discussion of this species see also Cooper, 1919: 460-73. Habitat. — Intestine of Gadus callarias L., the cod, Cheticamp, Cape Breton Island, Nova Scotia, September 13, 1917, and (?) Tautogolabrus adspersus W., the cunner, at the same locality, June 28, 1917. The material from the latter host consisted of several gravid portions of strobilas, very much contracted and degenerated, which I was not able to locate with certainty. They probably belong to this species ana their condition may be due to their having been picked up as very old fragments by the fish and their having failed to continue their existence in the cunner, which is not normally a host of A . rugosum. Abothrium crassum (Bloch 1779) This species has also been dealt with at length by the writer elsewhere (1919: 474-88). Habitat. — Intestines of the following hosts: — THE OCCURRENCE OF ABOTHRIUM CRASSUM IN HOSTS OF ARCTIC AMERICA. Host. Locality. Date. C.A.E. Stn. Accompanied by. "Salmon(Dog-Saimon?)" Port Clarence, Teller, July 31, 1913.... 20d Alaska. Cristivomer namaycush. . . . Lake at Bernard harbour, June 15, 22, 26, 40/,flr,t Echinorhynchus * Northwest Territories. 1915. salvelini. E. coregoni. (i « 1C « April, 1916 500 E. salvelini. E. coregoni. C. americanus. Salvelinus marstoni It (t Oct. 1,2, 1915... 42o,r E. coregoni P. arcticus. *See "Acanthocephala", Vol. IX, Part E: 5-6, of this Report, by H. J. VanCleave. Order II TETRAPHYLLIDEA Carus 1863 Family PROTEOCEPHALIDAE LaRue 1914 Genus Proteocephalus Weinland 1858 Proteocephalus arcticus, sp. nov. (Figs. 8, 12.) Specific diagnosis. — With the characters of the genus. Small cestodes from 8-5 to 15 mm. in length and 0-80 to 1-02 mm. in breadth. Scolex short, some- what flattened, truncated, unarmed, 0-30 mm. in length by 0-43 in width. Four suckers, muscular, with deep cavities, slightly directed forward, circular in outline, 0-18 mm. in diameter. Fifth sucker vestigial. Neck not well differen- tiated from strobila, about 1 • 8 mm. in length by 0 • 32 in width. Surface smooth; segmentation evident only in posterior one-third to one-half of strobila, posterior margins of segments do not protrude, lateral margins convex, transverse inter- segmental furrows shallow; 15 to 20 proglottides in all. First proglottides much broader than long, 0-45 to 0-50 mm. by 0- 18 to 0-22; mature segments about 16 G-H Canadian Arctic Expedition, 1913-18 quadrate or somewhat broader than long, 0-72 in width by ()• -is i«. u-(iO in length; ripe joints quadrate to somewhat longer than broad, '0-84 to 1-00 long by 0-68 broad; tormina! segment pointed. Genital organs as in genus. Genital pore marginal on a very low papilla, about two-fifths of length of proglottis from anterior border of same, irregularly alternating from right to left. Testes arranged in two partial layers between the vitellaria, 50 to 70 in number, spheroidal in shape, 55 to 100/x in diameter. Vas deferens a mass of coils in middle of segment, 0-16 to 0-20 in diameter. Cirrus-sac, 0-36 to 0-40 mm. in length by 0-14 to 0-18 in diameter, extending to near the median line of the segment, lying at right angles to margin of same. Cirrus straight in cirrus- sac, Vagina opens anterior to cirrus-sac, lies ahead of it for two-thirds of its i cirrus-sac's) length and crosses it ventrally at the beginning of the inner one- third or one-quarter of the same. Small vaginal sphincter, 50ju in diameter, near its opening. Vagina 18/x in diameter just within sphincter, 15ju where it turns posteriorly. Receptaculum seminis anterior to ovary, 20 to 30/z in diam- eter; spermiduct, 9 to 12/i. Ovary bilobed, lobes ovoidal; whole organ 0-58 mm. in width by 0-12 in length. Oocapt, 25 to 30/z in diameter; oviduct, 25/z. I terns with 6 to 9 diverticula on each side, anterior end broadly rounded, whole organ, 0-48 to 0-54 mm. in width by 0-64 to 0-70 in length. Uterine pore usually single (sometimes in the form of two separate openings). Embryo, 20 to 25/i in diameter. Type host. — Salvelinus marstoni Garman, red Canadian trout, in posterior portion of intestine, in company with Abothrium crassum and Diphyllobothrium sp. larv. (vide supra). Type locality. — Lake at Bernard harbour, Northwest Territories, Canada; C.A.E. Stations 42o and 42r. Collected by Mr. Frits Johansen, October, 1915. Cotypes are deposited in the Victoria Memorial Museum, Ottawa, Canada, (Annelids, etc., Catalogue No. 82), and in the collection of the writer at Chicago, Illinois, U.S.A. This species resembles P. filicollis (Rud.) and P. esocis (Schneider) as described by LaRue (1914) in that the testes are arranged in two partial layers and the latter in that the cirrus-sac extends about half way across the proglottis, but it otherwise represents an aggregate of characters, many of which individually or in small groups resemble those of other species of the genus. Order III CYCLOPHYLLIDEA Beneden Family I DILEPIDIDAE Railliet et Henry 1909, e.p. Liihe 1910 Subfamily DILEPIDINAE Railliet et Henry 1909 Genus I Lateriporus Fuhrmann 1908 Lateriporus geographicus, sp. nov. (Figs. 9, 13, 14). Specific diagnosis. — With the characters of the genus. Medium sized cestodes at least 172 mm. in length by 2 • 0 in diameter. Scolex almost spherical, 0-56 mm. in length by 0-62 in width. Rostellum stout and truncate, at least 0-16 mm. in length by 0-30 in diameter; nature and arrangement of hooks not observed. Suckers unarmed, not especially prominent, nearly circular in outline, 0-28 mm. in length by 0-24 in width. Unsegmented neck about 1-1 mm. in length by 0-45 in diameter, constricted to 0-28 mm. immediately behind the scolex; shows many transverse rugae closely resembling the foremost segments Trematodes and Cestodes 17 G-H but due to longitudinal contraction. Anterior segments infundibuliform but much broader than long; middle, more nearly quadrate and about twice as broad as long; posterior, less than twice as broad as long with convex lateral borders, 1-40 mm. in length by 1-95 in breadth. Genital pore at the middle of the lateral border of the segment on a low rounded papilla, 0-2 mm. in diameter by 0-08 in height and in many segments retracted so that its summit is level with the edge of the proglottis. Opening of vagina immediately ventral to that of cirrus at the bottom of a genital cloaca, 0-125 mm. in depth by 0-036 in diameter. Testes arranged in two or three layers posterior, lateral and somewhat dorsal to the central glands and ducts of the female organs; 15 to 20 in number, spheroidal in shape, 80 to 120^ in diameter. Proximal coils of vas deferens median and near the anterior border of the segment, distal less compact coils surrounded by numerous highly vacuolated glandular cells; no external seminal vesicle. Cirrus-sac almost cylindrical in shape, short and stout, 0-24 mm. in length by 0-07 to 0-09 in width. Cirrus very short and thick and armed with a host of minute stout spinelets. Vagina thick-walled and muscular from genital cloaca to within the ventral excretory vessel, about 0-11 mm. beyond which it turns abruptly dorsally then medially to become the receptaculum semmis; laterally it courses directly beneath the cirrus-sac but medially it diverges posteriorly. Seminal receptacle ellipsoidal in shape, 0-15 mm. in length by 0-12 in diameter. Ovary median, semiannular in shape, with the forwardly directed convexity bearing about ten short, stout tubules; whole organ, 0-15 mm. in width by 0-09 in length. Shell- gland inconspicuous. Vitelline gland median, spheroidal in shape, about 70/x, in diameter. Uterus composed of a median short and slightly coiled canal, leading to a main A-shaped stem, from which numerous saccular lobules invade the parenchyma in all directions (Fig. 14). The lateral lobes enlarge before the more median ones, and the whole organ eventually fills up the whole of the medullary parenchyma. Eggs, measured in toto preparations cleared in oil of wintergreen, 0-125 to 0-145 mm. in diameter, oncospheres 55/i in diameter. Type host. — Somateria v-nigra Gray, the Pacific eider, in the stomach, in company with Aploparaksis sp. and Fimbriaria intermedia. Type locality. — Bernard harbour, Northwest Territories, Canada; C.A.E. Station 49r. Collected by Mr. Frits Johansen, June 27, 1916. The paratype is deposited in the Victoria Memorial Museum, Ottawa, Canada, (Annelids, etc., Catalogue No. 83). This species obviously does not belong to Lateriporus teres which was described by Krabbe (1869:284) and Fuhrmann (1907:521) from Somateria mollissima, the European eider, from Greenland. It resembles, however, one of the other four species of Lateriporus, namely L. biuterinus Fuhrmann (1908: 56), which was taken from a number of South and Central American birds as well as from the European Oidemia fusca (L.), the velvet scoter, a close relative of Somateria, in that the uterus is divided into two parts at the median line and each of these is subdivided into a number of lobules. But the lobulation is carried on to a much greater extent in L. geo- graphicus, as indicated in figure 14, which represents three stages in the develop- ment of the organ. Eventually the two main limbs come close together in the median line posteriorly and the whole parenchyma, cortical as well as medullary, becomes filled with the eggs. On the other hand, L. geographicus differs from L. biuterinus in that there is no seminal vesicle just outside of (median to) the cirrus-sac ; the vagina opens ventral to the cirrus instead of ahead ; the receptac- ulum seminis, vitellme gland and ovary are much smaller; the ovary is differently shaped and lobulated; and, finally, the oncospheres are much larger (55/z vs. 9133-2 18 G-H Canadian Arctic Expedition, 1913-18 24/z in L. &.). The specific name chosen has reference to the map-like contour of the uterus. Genus II Choanotaenia Railliet 1896 Choanotaenia passerellae, sp. nov. (Figs. 10, 15.) Specific diagnosis. — With the characters of the genus. Small oestodes at least 20 mm. in length by 0-95 in maximum breadth. Scolex small, conoidal, aUmt 0-14 mm. long by 0-20 wide. Rostellum cylindrical and spheroidal at tip, 72/i wide; nature and arrangement of hooks not observed. Suckers i manned, prominent especially posteriorly, circular in outline, at least 90/x in diameter. Unsegmented neck about 0-16 mm. long by 0-20 wide. Anterior proglottides very short; middle infundibuliform and much narrower anteriorly than posteriorly; hindermost, 1-72 mm. in length by 0-95 in width, with some- what convex lateral borders and more nearly the same width at their anterior borders as at their posterior borders. Genital pores irregularly alternating, located two-ninths of length of segment from its anterior end. Vaginal opening posterior to and on the same horizontal plane with that of cirrus. Genital cloaca unarmed. Testes massed in the posterior two-fifths of the segment and surrounding the vitelline gland, 20 to 25 in number, each with maximum diameter of 75/*. Coils of vas deferens median and close to anterior border of segment, 0-15 to 0-20 mm. in diameter. Cirrus-sac, elongated, spindle-shaped, 0-25 to 0-27 mm. in length by 56/z in diameter. Vas deferens coiled proximally in cirrus-sac, straight distally. Cirrus at least 55 to 70/i in length by 18ju in diameter, armed with small, stout pines. Vagina lies posterior to cirrus-sac and after crossing the large ventral excretory canal is dilated to form an elongated seminal receptacle, the proximal end of which, almost median in position between the ovarian lobes, may be as much as 70/x in diameter when filled with spermatozoa. The bilobed ovary, 0-32 mm. in length by 0-36 in width, occupies the whole of the transverse diameter of the segment between the excretory canals. Each lobe is composed of tubular lobules radiating from a median isthmus about 0-08 mm. in length; that situated on the side bearing the genital apertures is much shorter than the other. Shell-gland median, compact, almost spherical in shape, 70/z in length by 45 in width. Vitelline gland median behind the shell-gland, compact, irregu- lar in shape, 130/* in length by 110 in width. The gravid uterus fills most of the segment, extending beyond the excretory canals on each side. Eggs almost spherical in shape, 25 to 30/i in diameter, contents (before cleavage had set in) at least 20ju. Type host. — Passerella iliaca (Menem), the fox sparrow, in the stomach, in company with Aploparaksis elisae Skrjabin. Type locality. — Teller, Alaska. Collected by Mr. Frits Johansen, August 3, 1913. Cotypes are deposited in the Victoria Memorial Museum, Ottawa, Canada, (Annelids, etc., Catalogue No. 84), and in the collection of the writer at Chicago. Although I did not observe the nature and arrangement of the hooks on the rostellum of this form, these having evidently been all torn away from the only two scolices in the small lot of material collected, I consider this species to be new, since in other regards it differs more or less considerably from the species of Choanotaenia, the descriptions of which were available. It closely approaches however, C. parina (Dujardin 1845) which is found in Passer domesticus (L.) and other passeriform birds, as shown by the following excerpts from the, brief description by MaroteJ (1899) of that species:— Trematodes and Cestodes 19 G-H "2 to 3 cm. in length by 0-8 mm. in width. 4 unarmed suckers, 22 to 27 hooks, 19 to 20/i in length, on the rostellum. Neck short, very slightly narrower than the head. About 80 segments; posterior borders projecting, last a little longer than wide. Reproductive openings very irregularly alternating, one-fifth of length of segment from anterior edge. 20 to 25 testes, ellipsoidal, large, axis transverse, located in a little more than the posterior one-third of the segment. Coils of vas deferens in anterior one- third of segment. Two kinds of spines on cirrus; short and stout towards the summit, fine and slender at the base. Ovary with two lateral wings in middle third of segment. Vitelline glands immediately anterior to testes. Vagina opens into a narrow, cylindrical genital cloaca, behind and on the same horizontal plane as the cirrus. Receptaculum seminis between ovarian wings and ahead of yolk gland, not very voluminous and scarcely central. In Sturnus vulgaris." Nevertheless, the differences between the two forms seem to be sufficient to warrant the erection even in the absence of the rostellar hooks of a new species, the first of this genus, so far as I know, to be described from Passerella iliaca. Family II HYMENOLEPIDIDAE Railliet et Henry 1909 Subfamily I HYMENOLEPIDINAE Ransom 1909 Genus Hymenolepis Weinland 1858 Subgenus Aploparaksis Clerc 1903 Aploparaksis elisae Skrjabin 1914, e.p 1914: Aploparaksis elisae SKRJABIN : . . . . 1914: 451 (Type host, Fuligula nyroca; Talass River, near Aulie-Ata, Turke- stan.) Specific diagnosis. — With the character of the genus. Medium-sized cestodes with a length of 120 mm. by a maximum breadth of 1 • 4 mm. Rostellum (half retracted) 30ju in diameter at base; bears ten hooks, each 25-9^ in length. Anterior segments (where first uteri appear), 0-08 mm. in length by 0-60 to 0-64 in width; posterior (gravid), 0-12 mm. long by 0-93 to 1-4 wide; second last proglottis, convex laterally and freed of most of its eggs, 0-20 mm. long by 0-48 wide. Posterior borders of all but the hindermost segments salient, giving the strobila a fine saw-toothed appearance laterally. Genital pore situated slightly ahead of, at, or slightly behind the middle of the margin of the segment. Opening of vagina immediately ventral to that of cirrus and at the bottom of a very shallow, funnel-shaped genital atrium, 12^ in dorsoventral diameter and lOju. in transverse diameter (depth). Testis median, spheroidal in shape, fills up the whole of the segment antero- posteriorly, 0-10 to 0-12 mm. in length by 0-15 to 0-19 in width by 0-11 to 0-12 in depth. Testes are so large that those of consecutive proglottides push by each other and hence often appear as two rows along the strobila. Outer seminal vesicle oval or ellipsoidal in shape, dorsal to inner end of cirrus-sac, 0-110 mm. in transverse diameter (its length), 0-035 and 0-45 in dorsoventral and longitudinal diameters, respectively. Width of proximal coils of vas deferens, 90/*, length, 36/z. In young segments the cirrus-sac extends to the median line; in ripe joints it occupies only one-quarter of the transverse diameter of the strobila; 0-26 to 0-28 mm. in length by 0-023 to 0-027 in diameter. Inner seminal vesicle, 0-172 mm. long by 0-018 in diameter. Cirrus unarmed, 0-110 to 0-125 mm. in length (within the sac). Most of the vagina is enlarged to form a very large seminal receptacle which extends from just within the genital atrium to past the median line, 20 G-H Canadian Arctic Expedition, 1913-18 filling up the whole of the proglottis anteroposteriorly below the cirrus-sac; 0-29 to 0-34 mm. in length by 0-070 to 0-072 in diameter. Ovary somewli.-it Mlobed and tabulated, 0-135 to 0-32 mm. in width by 0-045 to 0-065 in length by 0-35 in depth Vitelline gland ellipsoidal, median, posterior to ovary, 50 to 60ju in diameter. Uterus when first apparent in toto preparations occupies the middle third of the proglottis transversely, when gravid extends well beyond the excretory vessels which appear in transections nearly surrounded by the organ on account of its being somewhat tabulated dorsoventrally. The receptac- ulum seminis likewise appears imbedded in the dorsal side of the poral half of the uterus. Length of uterus, 0-12 to 0-15 mm., width, 0-75 to 1-00, depth, 0-12 to 0-28 (these differences due to the tabulation). Eggs spherical; outer envelope, 56/-1 in average diameter, middle, 37;*, oncosphere, 26 to 30/x. Habitat. — Stomach of Passerella iliaca (Merrem), the fox sparrow, in com- pany with Choanotaenia passerellae Cooper, sp. nov.; Teller, Alaska, August 3, 1913. To this species I refer six strips of proglottides without scolices, two of them evidently belonging to the same worm, having a combined length of 56 mm. and maximum breadth of 1 -2 mm. Their anatomy agrees with the brief description given by Skrjabin, excepting only for the facts that the antiporal borders of the testes do not extend to the antiporal excretory vessels and the ovaries are much narrower— 0-135 to 0-165 mm. rather than 0-29 to 0-32 ("with a width of proglottis of 1-02 mm.") of Skrjabin. Skrjabin's description is slightly amended to include the latter data, while other specific characteristics are here given for the sake of a clearer definition of this, one of the largest of the species of Aploparaksis. Aploparaksis sp. To this genus I also refer a lot of small and poorly preserved cestodes taken from the posterior portion of the intestine of a specimen of Somateria v-nigra Gray at Bernard harbour on June 27, 1916, at C.A.E. Station 49r. The lot con- sists of portions of at least two worms, much coiled, without scolices and in such a poor state of preservation that I was unable to ascertain to what species they belong. However, they resemble A. birulai Linstow (1905:8), so far as I know the only species of Aploparaksis which has up to date been found in a species of Somateria, in the following points : The length is approximately the same (27 • 5 mm. vs. 24-8 mm. for A. 6.); the longitudinal muscles are disposed in two layers, an outer among the subcuticular cells and an inner and much stronger in the usual position; there are no calcareous bodies; the genital pore is unilateral and opens in the middle of the lateral border of the segment; the testis is spherical in shape and its diameter is about one-tenth of that of the segment; the cirrus-sac is one-third the diameter of the proglottis in length, namely, 0-16 mm. (by 36/z in diameter); the cirrus is cylindrical and heavily armed; the vagina is situated ventral to the cirrus-sac; the receptaculum seminis, 37 to 50/x in diameter, is ventral to the ovary; and finally the eggs are 37/x (the embryo 25/i) in diameter — 40 by 34ju in A. b. On the other hand they differ from A. birulai in that the lengths of the proglottides are anteriorly, 54/z (vs. 12/x), posteriorly, 60/z (19/z) and when ripe lOlju, while the respective widths are 0-24 mm. (0-13 mm.), 0-38 (0-57) and 0-48 (0-25); the cirrus is much larger, 0-145 by 0-015 mm. (0-023 by 0-0052); and the testis is more median in position. I was able to determine neither the positions nor the courses of the excretory vessels and the nerves. The lengths and widths of the ovary and uterus (when filled with eggs) are, respectively, 0-054 and 0-127 mm., and 0-11 and 0-38 mm. Trematodes and Cestodes 21 G-H Subfamily II FIMBRIARIINAE Wolffhtigel 1899 Genus Fimbriaria Frolich 1802 Fimbriaria intermedia Fuhrmann 1913 Habitat. — Intestine of Somateria v-nigra Gray; Bernard harbour, North- west Territories, June 27, 1916; C.A.E. Station 49r. This species has been well described by Fuhrmann (1913:446-52). A study of the seven specimens and portions of specimens at hand brought out a few differences of dimensions which seem worthy of note: The largest specimen, incomplete posteriorly, was 55 mm. in length (vs. Fuhrmann's 30 to 40 mm.) by 2-5 in width (vs. 1 to 1-5), its pseudoscolex, 2-3 by 1-5 mm.; the calcareous corpuscles in the parenchyma gave maximum dimensions of 12 by S/*; a typical longitudinal muscular fascicle near the median line was 21ju in dorsoventral diameter by 9 in transverse; the cirrus-sac was on the average larger, namely, 0-34 mm. in length by 0-036 in diameter (vs. 0-2 by 0-03); both the external seminal vesicle and the seminal receptacle were much enlarged with sperma- tozoa, the latter so much so, in fact, that it was larger than the former — a temporary condition no doubt; the ovary was from 0-8 to 0-9 mm. in width; the vitelline gland was located a little closer to the antiporal border of the ovary than to the poral margin and was 0-13 mm. in width by 0-11 in length; eggs ellipsoidal in shape, 36 by 27/z in dimensions, embryos spherical, 22n in diameter. By placing the genus Fimbriaria in the family Hymenolepididae I am fol- lowing the advice of Fuhrmann (1913:456) who has emphasized the many characters common to the two groups and the impossibility of maintaining the family Fimbriariidae. However, on account of its very aberrant structure it must be separated considerably from the other genera of the family, hence the use of WolffhiigePs subfamily name Fimbriariinae. Family III TAENIIDAE Ludwig 1886 Genus Taenia Linneus 1758 Taenia coenurus Ktichenmeister 1853 To this species I refer a lot of ten isolated proglottides taken from the foeces of one of the dogs of the expedition at Collinson point, Alaskan arctic coast, on September 23, 1913. Although they are past the gravid stage, each containing only a few eggs, and the central reproductive glands and ducts are all but completely degenerated, they agree so well with the description of the species given by Deffke (1891) that there can be no doubt as to their identity. They vary in length from 7-0 to 8-0 mm. and in maximum diameter from 2 to 2-8 mm.; the dimensions of the cirrus-sac are 0-32 by 0-08 mm.; there are from 15 to 18 lateral uterine diverticula ; and the eggs are nearly spherical and from 30 to 37 /z in maximum diameter. College of Medicine, University of Illinois. 22 G-H Canadian Arctic Expedition, 1913-18 LITER A'lTKM CITED.* Bergendal, I>. ISD'J. Kur/or li-.-rirlit iiht-r cine ini S.MMMKT dcs .Jalirc> IS'.M) UMtcnioniiiicnc ioplqnsche Raise naoh ISTordgrOnland. Bihang Kgl. Svenska Vet.-Akad.. Handlingm-, 17 I Comini, E. 1SS7. Die Internationale I'<>1 iH'.dirt 1SS2/83. Die ostcrivichis.-lic I'olarstalion .Ian Mayon. Boobachtungen und Ergolmisso, III, \Virn, is.sT. Cooper, A. R. 1917. A Morphological Study of Hot hriooophalid Cestodes from Irishes. .lourn. Parasit., 4: 33-39, 2 pis. l'.>19. North Ani'-ricaii Pseudophyllidean Cestodes from Fishes. 111. Biol. Monogrs., 4: 289-541, 13 pis. 1920. Glaridacris catostomi gen. nov., sp. nov.: A Cestodarian Parasite. Trans. Amor. Micr. Soc., 39:5-24, 2 pis. Deffke, O. 1891. Die Entozoen des Hundes. Arch. wiss. prakt, Thierheilk., 17: 1-60, 2">:;-v.». Taf. I, II. Fabricius, O. 1780. Fauna groelandica, systematice sistens animalia Groelandiae occidentals haetenus indi^ata, elo. 470 pp., 1 pi. Hafniae et Lipsiae. Fuhrmann, O. 1907. Bckannte und neue Artrn und Genera von Vogjltanicn. Centrbl. Bakf ., Orig. 45: 516-38. 1908. Nouveaux t6nias d'oisaaux. Rev kiuiss3 Zool, Geneva, 16: 27-73, figs. 1-60. MU3. Sur 1'origine de Fimbriaria fasciomris Pallas. IXe Congres Intern. Zool., Monaco: 437-67. ( Jcnnanos, N. K. 1895. Bothriocephalus schistocMlos n. sp. Ein neuer Cestode aus dern Darin von Phoca barbata. Jen. Zschrft. Naturw., 30, n.f. 23: 1-38, 2 pis. Krabbe, H. 1865. Helminthologiske Unders